Array-based distributed storage systems are well known. These systems distribute data over two or more different disks to improve data access times, provide fault tolerance, or both. Distributed storage systems can employ different RAID configurations, as described in “A Case for Redundant Arrays of Inexpensive Disks (RAID),” by David Patterson et al., SIGMOD Conference: pp 109-116, (1988), which is herein incorporated by reference.
One high performance distributed storage system is sold by Avid Technology, Inc. of Tewksbury, Mass. under the Unity ISIS® trade name. This system is described in more detail in U.S. Pat. Nos. 7,111,115 and 6,785,768 as well as in published application numbers 2007/0083723 and 2007/0136484, which are all herein incorporated by reference. In the ISIS® system a redundant copy of all data is stored on a different drive in an array. If a drive fails, therefore, the redundant copies can be used to reconstruct it.